Adding blood vessels overcomes important limitations.

Scientists have taken cues from the “lost wax” technique for making renaissance bronzes to 3D print human mini-organs with their very own blood vessels.

It’s an advance that moves the field closer to creating life-saving organ transplants for the more than 100,000 people on US waiting lists alone, 20 of whom die each day.

Mini versions of the brain, kidney and heart – so-called “organoids” – have been grown in labs for the last decade to study diseases including dementia, cancer and heart attacks.

But those models have stayed tiny, up to the size of a lentil, because of a critical ceiling. They lack tubes that mimic blood vessels and so researchers have struggled to get oxygen and nutrients into their core.

That crucial limitation has, thus far, put the kibosh on organoids fulfilling their grail-like destiny – to become full size transplant organs right there in the lab, tailor-made from patients’ own cells and not subject to rejection.

Now researchers, led by Jennifer Lewis at the Wyss Institute for Biologically Inspired Engineering at Harvard University in the US, have come up with an ingenious way of sculpting channels that meander like real blood vessels through mini-organs.

It even comes with its own, rather gothic moniker – Sacrificial Writing into Functional Tissue, or SWIFT.

Read the full story at Cosmos magazine here